<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>五彩导航</title>
    <style>
        .nav a {
            width: 120px;
            height: 58px;
            line-height: 58px;
            color: #ffffff;
            text-align: center;
            text-decoration: none;
            display: inline-block;
        }

        .a1 {
            background: url(images/red-bubble.svg) repeat center center;
        }
        .a1:hover {
            background: url(images/g-bubble.svg) repeat center center;
        }

        .a2 {
            background: url(images/g-bubble.svg) repeat center center;
        }
        .a2:hover {
            background: url(images/red-bubble.svg) repeat center center;
        }

        .a3 {
            background: url(images/b-bubble.svg) repeat center center;
        }
        .a3:hover {
            background: url(images/g-bubble.svg) repeat center center;
        }

        .a4 {
            background: url(images/y-bubble.svg) repeat center center;
        }
        .a4:hover {
            background: url(images/b-bubble.svg) repeat center center;
        }

        .mx {
            width: 300px;
            height: 300px;
            background-color: orange;
            color: orange;
        }

        .mx {
            background-color: pink;
        }
    </style>
</head>

<body>
    <div class="nav">
        <a href="#" class="a1">导航1</a>
        <a href="#" class="a2">导航2</a>
        <a href="#" class="a3">导航3</a>
        <a href="#" class="a4">导航4</a>
    </div>
    <div class="mx">
        <p>今天下雪了</p>
    </div>
</body>

</html>